Pattern-maker s scale



PATENT OFFICE.

JAMES T. OOVLEY, 0F LOWELL, MASSACHUSETTS.

PATTERN-MAKERS SCALE.

SPECIFICATION forming part of Letters Patent No. 503,528, dated August 15, 1893.

Application filed December 12, 1892. Serial No. 454,842. (No model.)

To all whom t may concern:

Be it known that I, JAMES T. CoWLEY,a citizen of the United States, and a resident of Lowell, Middlesex county, Massachusetts, have invented certain new and useful Improvements in Scales, of which the following is a specification.

In the accompanying drawings, I have illustrated the preferred embodiment of my invention, in which- Figure 1, is a plan view of a rule having my invention applied thereto; and Figs. 2 and 3, are similar views of other rules, showing different embodiments of my invention.

The rule A may be of any of the usual forms and proportions, either a fiat, continuous strip, as shown in Fig. l, or it may be a folded rule as is common, and of any of the usual lengths from six inches to a number of feet, and the rule is graduated upon one or both sides in the conventional manner into inches and fractions thereof. In addition to the ordinary graduatons which if desired, may indicate only the inches as in Fig. 3, but preferably is subdivided as in the other figures. I engrave, stamp, or otherwise place upon the rule, supplemental lines, b, b or b2, b3, which instead of being parallel to the edges of the rule, are at different angles thereto. The angles at which the supplemental lines are placed are determined by the extent of expansion or shrinkage of an object formed from a pattern, in the making or designing of Which the rule is employed.

As is well known, in making of patterns for castings, itis necessary to allow for the shrinkage of the particular metal or composition used in making the castings, and if the casting is to be a pattern casting, from which molds are to be taken and from which other castings of different metal are to be employed, it is necessary to estimate, not only the shrinkage of the final metal from which the actual product is made, but also the shrinkage from which the second or metallic pattern is made.

It has heretofore been customary to make use of arbitrary rules, so graduated that each space indicating an inch of measurement (and the subordinatemeasurement or graduations) exceeded in size the conventional inch and subordinate divisions in proportion as it was necessary to compensate in the pattern for the reduction that would result from the shrinking of the metal in the casting formed from said pattern. This, of course, necessitates the employment of a large number of rules of different dimensions, which it is the object of my invention to avoid, while I also secure the advantage of using the rule for measuring according to the conventional standard. Forinstance, in a rule which is to be used for making or designing a pattern to be cast from brass, where it is necessary to compensate for a shrinkage of three-sixteenths of an inch per foot, I deflect the line b to the extent of three-sixteenths of an inch in each foot of space occupied by said line upon the rule, that is, in each foot of length, the line at one end of the foot of measurement is three-sixteenths of an inch farther from the edge than at the other end, and the pattern maker therefore, in using said rule, in laying off one, two, three or more inches upon the pattern adds to the conventional measurement (as say, three inches,) the additional length constituting the perpendicular of the triangle formed by the line b, the said perpendicular and the base line at right angles to the perpendicular which extends to the point where the line l) starts. This point may be either the edge of the scale or rule as in Fig. 3, or the end of aline a parallel to the edge of the rule as in Fig. l. In a rule which is to be used for making a pattern for iron castings where the shrinkage is one-eighth of an inch per foot, the angle of the line h', Fig. l, is that resulting from placing the termination of the said line at oneeighth of an inch distance farther from the edge of the rule, that is if the rule is twelve inches in length and in the same proportion for other lengths.

When the wood pattern is to be used for making a brass pattern from which the molds are to be made, for castings from iron, an allowance must be made, first, for the shrinkage of the brass and then for the shrinkage of the iron, and I place the line as indicated by 133 live-sixteenths of an inch farther from the edge at the termination of the foot measurement than at the beginning; five-sixteenths equaling the combined shrinkage of brass and iron, or where the final casting is of brass, I place the termination-of the line as at b2, three eighths of an inch farther from the edge at one end than .at the other, which equals the double shrinkage, rst, of the brass pattern casting and then of the brass product casting. It will be evident that these lines properly marked to indicate their character may be placed upon opposite sides of the same scale or all upon the same side.

Where it is desired to make use of a rule not over a footin length and at the same time secure the measurements for lengths in eX- cess of a foot, I make use of an additional llne as ma', placed at a distance from the edge of the rule equal to the shrinkage of the metal per foot from which the casting is to be made. For instance, the line a is placed at one-eighth of an inch from the edge of the rule and the line b is drawn from the beginning of the line ct at one end. Therefore 1n measurements exceeding a foot, it is only necessary to add to the conventional measurement in inches, three, four, or five, Whatever, it may be in excess of a foot, a length equal to the distance of the line b from the edge of the rule. Thus if the length is seventeen inches, (or iive inches more than a foot) five inches is measured off, and in addition the distance between the edge of the line b', a five inch graduation including the eighth of the inch between the edge and the line a and the additional distance to the line b. The line a parallel to another edge of the rule is placed at such distance from such edge as is equal to the shrinkage per foot of some other metal, as for instance, brassA Without limiting myself to the precise construction and arrangement shown, l claim as my invention-- l. A lineal rule for pattern makers use, provided with a line at au angle to the edge of the rule and crossing the inch divisional lines, the line being a distance from the edge at each inch line, equal to the lineal shrinkage of a metal in a length indicated at said inch line, substantially as described.

2. A pattern makers rule provided with inch graduations with a line, as a, parallel to the edge thereof, at a distance equal to the shrinkage per foot of a metal used in casting, and with a supplemental line, as b, beginning at the end of said line a, and at an angle thereto that forms a triangle having a perpendicular equal in a foot of length to the eX- tent of said shrinkage, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of tWo subscribing Witnesses.

JAMES T. COWLEY.

Witnesses:

EMMA F. COWLEY, KIRBY F. CHASE. 

